Carbonaceous materials have been recognized as one of the most promising anode materials for potassium-ion batteries (PIBs) due to their abundant raw materials, controllable structure, superior conductivity, and good chemical inertness. However, the large radius of K ions and the low potassium content of intercalation compounds result in the sluggish storage kinetics and low reversible capacity of carbon anodes. In this work, we present a unique heteroatom-doped carbon composite (denoted as NS-MC/SC) through a facile interfacial assembly route and simple heat-treatment process, where NS-MC is well grafted onto the biomass-derived spore carbon (SC). This unique structural design endows it with abundant mesoporous channels, expanded layer spacing, and highly doped N and S. With these merits, the NS-MC/SC anode in PIBs exhibits a high reversible capacity of 350.4 mAh·g⁻¹ at 100 mA·g⁻¹ after 300 cycles, and an outstanding cycling stability. Besides, in-situ Raman spectra further verify the high reversibility of K ions insertion/extraction. Importantly, theoretical simulations also reveal that the N,S dual-doping is an efficient approach for improving the potassium-ion storage performance of NS-MC/SC.

Mesoporous carbon nanomaterials have shown a great application potential in energy storage and conversion fields due to their outstanding conductivity, tunable pore structure, and good chemical stability. Nevertheless, how to accurately control the pore structure, especially directly assembling the mesoporous carbon onto different substrates remains a big challenge. Herein, we have successfully assembled two kinds of highly nitrogen-doped mesoporous carbon onto carbon nanotubes (NMC/CNTs) based on a facile cooperative assembly process assisted by triblock PEO₂₀PPO₇₀PEO₂₀ (P123) and PEO₁₀₆PPO₇₀PEO₁₀₆ (F127) copolymers. The experimental results indicate that the P123/F127 mass ratio has a profound effect on the pore structure, leading to the formation of NMC/CNTs composites with spherical pore structure (S-NMC/CNTs) and cylindrical pore structure (C-NMC/CNTs). In virtue of fast electron/ion transfer kinetics, the as-prepared S-NMC/CNTs anode demonstrates an excellent electrochemical performance for lithium-ion batteries, and it delivers a high reversible capacity of 588.1 mAh∙g⁻¹ at the current of 0.1 A∙g⁻¹ after 100 cycles, along with a superior cycling stability. Specifically noted, the controlled assembly route developed in our work can also be applied to other support materials with different structures and compositions.

Hollow nanostructures have attracted considerable attention owing to their large surface area, tunable cavity, and low density. In this study, a unique flower-like C@SnO_X@C hollow nanostructure (denoted as C@SnO_X@C-1) was synthesized through a novel one-pot approach. The C@SnO_X@C-1 had a hollow carbon core and interlaced petals on the shell. Each petal was a SnO₂ nanosheet coated with an ultrathin carbon layer ~2 nm thick. The generation of the hollow carbon core, the growth of the SnO₂ nanosheets, and the coating of the carbon layers were simultaneously completed via a hydrothermal process using resorcinol-formaldehyde resin-coated SiO₂ nanospheres, tin chloride, urea, and glucose as precursors. The resultant architecture with a large surface area exhibited excellent lithium-storage performance, delivering a high reversible capacity of 756.9 mA·h·g^–1 at a current density of 100 mA·g^–1 after 100 cycles.

The assembly of hybrid nanomaterials has opened up a new direction for the construction of high-performance anodes for lithium-ion batteries (LIBs). In this work, we present a straightforward, eco-friendly, one-step hydrothermal protocol for the synthesis of a new type of Fe₂O₃-SnO₂/graphene hybrid, in which zero-dimensional (0D) SnO₂ nanoparticles with an average diameter of 8 nm and one-dimensional (1D) Fe₂O₃ nanorods with a length of ~150 nm are homogeneously attached onto two-dimensional (2D) reduced graphene oxide nanosheets, generating a unique point-line-plane (0D-1D-2D) architecture. The achieved Fe₂O₃-SnO₂/graphene exhibits a well-defined morphology, a uniform size, and good monodispersity. As anode materials for LIBs, the hybrids exhibit a remarkable reversible capacity of 1, 530 mA·g⁻¹ at a current density of 100 mA·g⁻¹ after 200 cycles, as well as a high rate capability of 615 mAh·g⁻¹ at 2, 000 mA·g⁻¹. Detailed characterizations reveal that the superior lithium-storage capacity and good cycle stability of the hybrids arise from their peculiar hybrid nanostructure and conductive graphene matrix, as well as the synergistic interaction among the components.